Hello all. I have got this AIWA from Ebay as untested, the seller noticed that "put batteries in, and got nothing". So, luckily this player came with it`s original external battery compartment, and i opened it to see what is the problem: corroded battery contacts caused by leaked battery. The capacitor inside looks good. So my question is: When i have cleaned the contacts and if it then gives 2 volts with fresh batteries trough regulator, can i safely snap it on and try player itself? I meant that if there is leaked capacitors or something else electronical failure, is there risk of burn something like microprocessor chips? I have already the service manual (downloaded from here, thanks) and also new belt, but i haven't open device yet.
I had some time tonight to spend and also my separately bought power adapter arrived today, so i decided to take one step with this stuff. After got battery compartment cleaned and measured that it gives ca 2,5 volts with new batteries, which was same result than from wall adapter, i put it in place, and of course also cassette in. And nothing happens. There was still problems with contacts. With adapter plugged this Aiwa finally starts showing some signs of life - snaps from phones when i slightly turning battery pack or plug. First thougt that there is all i can get, but surprisingly tape going to move and control buttons also responsed to pressing them. Like expected, the only sound heard from headphones was loudy motor hum or whatever. But play, stop, ff and rewind functions seems to run as they should. Only the reverse play cannot engaged on this test. Thoughts?
Replace belt and re-cap the Walkman. For the battery pack not working, check the connections to the mainboard from the battery pack, and then the traces from the power connector. Very often the connector pins will gain in resistance over time, in which case, add Deoxit D5. If there is electrolyte leakage from the old capacitors, you will need to clean it off with baking soda paste and isopropyl alcohol before re-capping. Form the 470uf caps, the best option is the UMW series on my capacitor list. http://www.stereo2go.com/forums/threads/list-of-common-walkman-capacitors-2017.1246/
Today i took the unit open and here is look from inside. There's some oxided areas but not so badly than it would to be?
Another picture from mechanism. Here all seems to be in working order. That bi-azimuth system is interesting.
Seems that there is no replacement for those 470uf 2v capacitors, they have 6mm diameter. There is almost no extra space around them, as you can see from my picture. This one have same diameter but doubles the height: ESK477M6R3AE3AA Is there any better options for replacing them? Will this "UMW0G471MDD" fit anyway? Edit: I was blind - now I have read again a list of common walkman capacitors and saw this one which could fit to my player: RF80E471MDN1PX becouse there is some space for extra height. Can i use this polymer type because those two are directly in headphone line?
There are 2 options here: 1. Offset UMW 470uf: There might be space to offset them diagonally 2x 8mm in that spot (extra 2mm needed per cap) , see if they interfere with the chassis side (headphone jack brace?) To offset, the capacitor leads will need to be bent at 2 right angles. 2. RF8 Should be a perfect fit, but keep in mind the sound signature will change vs the stock electrolytics. I would buy both models and see if you can fit the UMW first.
Thanks for responses bub. So, i need to check if there is enough space for offset install. Chassis may came very close when unit is assembled, and around the headphone socket came metallic support frame. But there seems to be some space in inner side of capacitors. (Now i have only that picture to look, i put unit in plastic box and left it to waiting better time to continue project) By the way, can i use same audio grade capacitor to replace one 470uf/4v which is in battery regulator? There original is bigger than those two. Just thought.
Now that we can browse the old db http://www.stereo2go.com/topic/inde...14111653432&content_oid=295011598229638071#40 Those are Nichicon UMW0G471MDD https://www.mouser.fr/ProductDetail/647-UMW0G471MDD Edit for disambiguation: I didn't have to shift them, they just fit in place.
Yes you can use the audio grade capacitor in the battery box, however, I suspect the polymer cap will actually be the better choice there, due to higher specs (low ESR). Ball000: Thanks for relinking your thread! This is what I'm talking about, old random threads! The UMW looks like a perfect fit. That thread should also help Michelle's logic problems with her PX303.
Now i found this which have same dimensions that UMW but isn't audio grade, however, when looking their datasheets, there is no any differences in their specs. NICHICON UMA0G471MDD Why to use it? So there is seller in Europe, TME electronic components, who offer most reasonable shipping costs than Mouser or Digikey. But sadly they haven't stock this capacitor in audio grade. Please tell if this isn't good choice.
